MADRID (Reuters) - Crown Prince Felipe will take his ailing father's place saluting military officers at Spain's national day parade on Saturday as expectations rise he may soon take over the troubled throne.
King Juan Carlos, 75, is recovering from hip surgery, his fifth operation in two years, and will miss the annual parade for the first time.
Palace officials say he does not want to abdicate. But public pressure is mounting as his health and image deteriorate.
Prince Felipe, 45, faces an uphill battle to win back Spaniards, who have soured on royals and political leaders during an economic crisis aggravated by corruption scandals and a widening gap between rich and poor.
But his low-key style could make him the perfect man to lead the House of Bourbon back into favour.
Friendly but more discrete than his jovial father, the prince has not been tarnished by a scandal that engulfed his sister Princess Cristina. Nor has he been implicated in lapses of judgment at the palace, such as the king's African safari trip at the height of the economic crisis last year.
"The king is out of action for months and meanwhile the prince will be doing all the keynote things the king normally does. The prince will become more and more visible," said a royal historian who requested anonymity.
For most of his reign, Juan Carlos has been a hugely popular figure. He played a key part in Spain's transition to democracy in the 1970s after four decades of General Francisco Franco's fascist dictatorship.
He won huge respect for his role in putting down an attempted military coup in 1981, a terrifying incident for older Spaniards marked by the 1936-39 Civil War.
Support for the monarchy is almost generational, said political consultant Rafa Rubio.
"Almost anyone of any political colour who has seen the monarchy in practice in Spain supports it, but those people are getting old and being replaced by younger people who don't understand it," he said.
The monarchy was Spain's most popular institution back in 1997. A survey last May showed it had slipped to 6th place.
Its popularity was dented by a scandal which saw Mr Inaki Urdangarin, the king's son-in-law, charged with embezzling 6 million euros (S$10.1 million) in public funds. The judicial investigation is still open and may yet implicate Princess Cristina, his wife.
In April 2012, the king broke his hip hunting in Africa just as Spain teetered on the brink of a bailout, prompting public fury. When it emerged he was accompanied by a lady friend, the uproar intensified. Juan Carlos made an unprecedented apology.